摘要
Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon(SOC) sequestration.We sampled soils from a long-term(25 years) paddy experiment in subtropical China.The experiment included eight treatments:(1) check,(2) PK,(3) NP,(4) NK,(5) NPK,(6) 7F:3M(N,P,K inorganic fertilizers+30% organic N),(7) 5F:5M(N,P,K inorganic fertilizers+50% organic N),(8) 3F:7M(N,P,K inorganic fertilizers+70% or-ganic N).Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment.The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha.The SOC densities of all fertilizer treatments were greater than that of the check.Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers.The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues.Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization.Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.
Field experiments provide an opportunity to study the effects of fertilization on soil organic carbon （SOC） sequestration. We sampled soils from a long-term （25 years） paddy experiment in subtropical China. The experiment included eight treatments： （1） check, （2） PK, （3） NP, （4） NK, （5） NPK, （6） 7F：3M （N, P, K inorganic fertilizers＋30% organic N）, （7） 5F：5M （N, P, K inorganic fertilizers＋50% organic N）, （8） 3F：7M （N, P, K inorganic fertilizers＋70% or- ganic N）. Fertilization increased SOC content in the plow layers compared to the non-fertilized check treatment. The SOC density in the top 100 cm of soil ranged from 73.12 to 91.36 Mg/ha. The SOC densities of all fertilizer treatments were greater than that of the check. Those treatments that combined inorganic fertilizers and organic amendments had greater SOC densities than those receiving only inorganic fertilizers. The SOC density was closely correlated to the sum of the soil carbon converted from organic amendments and rice residues. Carbon sequestration in paddy soils could be achieved by balanced and combined fertilization. Fertilization combining both inorganic fertilizers and organic amendments is an effective sustainable practice to sequestrate SOC.
基金
Project supported by the Special Fund for Agro-scientific Research in the Public Interest (No. 201003059)
the National Natural Science Foundation of China (Nos. 21077088,40901142,51008107,and 31000296)
the National Key Science and Technology Special Projects of Water Body Pollution Control and Management (Nos.2008ZX 07101-006 and 2008ZX 07528-005-003)
the National Science and Technology Support Program of China (No.2011BAD41B01)
